From Ottoman Turkish یلك (yelek), from Old Anatolian Turkish يَلَك (yélek), from Old Anatolian Turkish يَل (yél, “wind”) -ek (“noun forming suffix”), from Old Turkic 𐰘𐰠 (y²l²) yél, from Proto-Turkic *yẹl (“wind”).
Practice speaking and memorizing "yelek" and many other words and sentences in Turkish.